当调用标记为条件的方法时，指定的预处理符号的存在或不存在决定是否包含或省略此调用。

When a method marked as conditional is called, the presence or absence of the specified preprocessing symbol determines whether the call is included or omitted.

youdao

源文件中的这个点通常由一个词素进行标记，而预处理程序不会使用该词素作为一个语言符号，这表示它并不是一项预处理程序指令。

This point in the source file is usually marked by a lexeme that is not consumed as a token by the preprocessor, meaning one that is not a preprocessor directive.

youdao

预处理数字符号未曾种类或值；种类或值将在向整数文字量或浮点文字量获胜转换（作为第7 阶段的一局部，2.1）尔后获得。

Preprocessing number does not have a type or a value; it acquires both after a successful conversion (as part of translation phase 7, 2.1) to an integral literal token or a floating literal token.

youdao